The present invention relates to a centrifugal machine with central fed of the kind utilizable particularly in the alimentary field for obtaining fruit or vegetables juices. More particularly, the present invention relates to improvements in the fixing element for the unit "grater-filtering basket" of the centrifugal machine as well as to the pressing device thereof commonly called a "pestle". The pestle is employed for pushing the products to be treated in the feeding duct of such machines and permits the entire product to be introduced to a grater, with a consequent complete treatment thereof.
So-called "centrifugal machines" are well known in the alimentary field particularly for squeezing fruit and vegetables to obtain the juices thereof.
As is already known, centrifugal machines of various types have been provided with a central feed, coaxial to the working unit (grater-filtering basket) so as to be more efficient as well as smaller than other types of juice machines.
The machines provided with central feed which present different defects and operative restrictions have been progressively improved and among the most advanced and also the most recent types of machines, reference can be made to the improved machine described in utility model patent application n. 60323 B/87 filed in Italy on Feb. 27, 1987 by the present inventor.
However, in a machine of such kind, a transverse element is always provided at the lower end of the feeding duct near the upper surface of the scraping element (rotating grater). This transverse element, generally constituted by a thin lamina, is diametrically disposed with respect to said feeding duct and functions to prevent said scraping element from entraining in rotation the material (fruit or vegetables) introduced thereto.
The improvement described in the above-mentioned utility model patent application consists of providing an upset "V" groove in the surface provided at the pressing end of the pestle, in which groove said transverse element may extend so as to permit an almost complete penetration of the material to be worked.
This solution too, however, presents functional restrictions and drawbacks.
In fact, if pieces of fibrous products with ligneous consistency, such as carrots and the like, become oriented with their fibrous part extending transversely to said transverse element, the working thereof is difficult and often is performed in an incomplete way even when considerable thrusts are exerted on the pestle, which thrusts, however, cause a considerable fatiguing of the operator.